The present invention resides in the field of mechanics or micromechanics and can be applied advantageously in particular in medical technology.
The invention relates to a blade for a pump and the design thereof. Of concern thereby is a pump having a rotor, the rotor being compressible and expandable in order to be able possibly to change the overall dimensions of the pump. In this way, the pump can be pushed through not readily accessible openings or into narrow pipe systems, for which purpose it is firstly compressed and, after it has been moved to the location of use, is expanded again.
Such a pump can be used particularly advantageously in medical technology in the field of heart pumps or other pumps for body fluids which are normally used with catheters.
In the technical medical field, different types of micropumps are known, which pumps can be introduced in the compressed state with a catheter through a naturally occurring body vessel into the body of a patient and can be expanded in situ. In order to produce a corresponding radial compressibility and expandability, various effects can be used in the construction and the structure of the pump housing and the pump rotor, such as e.g. the use of so-called memory alloys which change their shape as a function of the ambient temperature or control the pump diameter specifically by providing specific transmission mechanisms which allow it.
A solution is known from DE 10 2004 054 714 A1 in which both the impeller of a micropump and the housing thereof is manipulated by a mutual axial displacement of the pump drive shaft. As a result, the housing is changed between a compressed and an expanded state.
A system is known from the patent document WO 00/2003103745 A2, in which the pump housing is likewise expanded mutually radially by an axial relative movement of two components.
A rotor is known from the US patent specification U.S. Pat. No. 7,393,181, the blade of which can be subdivided into a plurality of partial blades or rows of partial blades for improved compressibility/collapsibility. As a result of the subdivision, the individual partial blades are smaller than a one-part blade and almost flat so that they can be rolled in easily. However, the ability to be subdivided is restricted by the intrinsic stability of the partial blades which requires to be ensured.